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BHARATI PUBLIC SCHOOL, PITAMPURA, DELHI110034 BAL
Corequestionscontrol and coordination ClassX,subbiology( SA1) Q1.Differentiate between (i)tropic and nastic movements. (ii)axon and dendrites (iii)cerebrumand cerebellum. A. FEATURESGROWTH INDEPENDENTGROWTH DEPENDENT MOVEMENTSMOVEMENTS 1.Time of actionimmediate slow 2.Because ofchange in turgorcell division 3.Response to stimulusnondirectional directional 4.Also known asnastic movementstropic movements 5.Examples openingand closing ofphototropism,geotropism Stomata,foldingof leaves ofchemotropism,hydrotropism Touchmenot FEATURES AXONDENDRITES 1.Size and numberlong and onesmall and numerous 2.Branching generallyunbranched branched 3.Terminal knobsterminal branches haveabsent Swollenknobs 4.Direction of nerveaway from cell body(cyton)towards cell body impulse FEATURES CEREBRUMCEREBELLUM 1.Part offorebrain hindbrain 2.Size largestpart of brainsmaller part of brain 3.Location coversmost of the regions of headpresent just above the back of neck 4.Function associatedwith intelligence,memory,associated with voluntary muscular Voluntaryand involuntary muscularmovements ,maintain body balance Activitiesand posture Q2.How doesthe nervous tissue cause action? ANS. When a nerve impulse reaches the muscle,the muscle fibre must move by changing their shape.this is possible as muscle cells have special proteins that change both their shape and arrangement in the cell in response to nervous electrical impulses.when ths happens new arrangements of these proteins give the muscle different shapes. Q3.What are PHYTOHORMONES?give examples ANS.The chemical coordination occurs in plants with the help of certain chemicals ,called phytohormones. PHYTOHORMONES FUNCTIONS 1.AUXINS promotecell division, bending of shoot towards the source of light, 2.GIBBERELLINS stimulatestem elongation 3.CYTOKININ celldivision 4.ETHYLENE promotefruit growth and ripening (gaseous hormone) 5.ABSCISIC ACIDinhibit growth ,closing of stomata ,seed dormancy Q4.Which organ secreteshormone when the blood sugar rises?name a digestive enzyme released by this organ.
ANS. Pancreas secretes hormone insulin when sugar level rises.Digestive enzyme secreted by pancreas is trypsin(that digests protein). Q5.What will happen when plant is exposed to unidirectional light? ANS.Phototropism i.e. bending of stem towardsunidirectional flow of light. Q6.A particular hormone requires iodine for its synthesis.Name the endocrine gland which secretes this hormone and state its location in human body. ANS.Thyroid gland secretes thyroxin which requires iodine.it is located on the trachea below the voice box. Q7.How are our brain and spinal cord protected? ANS.Brain –inside bony cage called cranium or skull. Spinal cord—vertebral column. Q8.Identify the glands and mention hormones produced 1.Gland which prepares our body to function at maximum efficiency during anger or danger. 2.gland that helps in growth of bones and muscles. 3.gland that helps in growth of secondary sexual characters in males. ANS.1.adrenal gland, hormone is adrenaline. 2.pituatarygland, hormone is growth hormone 3.testes,testosterone. Q9. Mention some secondary sexual characters seen in both girls and boys during puberty. ANS.GIRLSgrowth of breast size,menstruation, high pitched voice,female pattern of hair distribution ,growth of genital organs. BOYSgrowthof hair on face(beard and moustaches),body arms,and legs ,husky voice,broad shoulders, penis size increases,growth of genital organs. Q10.Give reasons: a)why we must take iodised salt? b)why the touch –menot(Mimosa pudica)plantleaves droop when touched? ANS. a)iodizes salt contains iodine element which is required for thyroxine hormone,lack of iodine will not help in production of thyroxine and hence the thyroid gland will enlarge leading to goiterswelling in neck region. b)touchmenot plant cells are filed with water.on being touched at the base of leaf,these cells loose water and become flaccid so they droop .this type ofmovement is growth independent. Q11.Name two systems which together perform function of control and coordination in human being. ANS.(i)nervous (ii)chemical(hormones) Q12.Draw the labeled diagrams of the following(refer N.C.E.R.T) ANS.(i)A neuron,(ii)synapse,(iii)outline diagram of brain with erebrum,cerebellum,medulla,pons(iv)reflex arc(v) outline of human body with the locations of various endocrine glands. Q13.What is reflex arc? ANS.It is a rapid automatic, unconscious and involuntary response of the body to a stimulus without involving the brain. On application of stimulusreceptor>sensory neuronspinal cordmotor neuroneffector(muscle and glands). Examplesalivation of mouth at thought of good food,constriction of pupil in bright light, sneezing, removing hand on touching hot plate. Q14.What are the characteristics of animal hormones? ANS.1.They are secreted by endocrine glands directly into the blood. 2.they act away from theirsite ofproduction.
3.hormones are specific in their action. 4.They are required in small quantity. 5.deficiency or over secretions of hormones have negative effects in the body. Q15.Write the mechanism of adrenaline hormone? OR Why adrenaline is called emergency hormone? ANS.Adrenaline hormone is released into the blood from the adrenal gland during stimulation of the nervous system on seeing any adverse situation of fight or fright i)increases the blood pressure ii)increases heart beat rate iii)increases breathing rate iv)diverting blood to essential organs including the heart, brain and skeletal muscles by dilating their blood vessels and constricting those of less essential organs, such as the skin and digestive system. Q16.What is synapse? ANS.The functional junction between neurons for the transfer of information i.e. nerve impulse ,occurs from one neuron to the next. Q17.What regulates the timing and amount of release of hormones? ANS.This is regulated by feedback mechanisms for example,glucose level in the blood is maintained constant by either of the feedback mechanisms a)high glucose level in the blood induces the pancreatic cells to produce more insulin which converts glucose to glycogen. b)less glucose level in the blood does not induce the pancreatic cells to produce insulin so that less conversion of glucose to glycogen may occur. Q18.What is the role of Medulla? Ans. Many of the involuntary actions are controlled by the mid and hind brain. All these involuntary actions like: blood pressure, salivation, and vomiting are controlled by the medulla in the hind brain. Q19. What is the function of cerebellum? Ans. Activities like: walking in a straight line, riding a bicycle, picking up a pencil( precision of voluntary actions), maintaining the posture and balance of the body are controlled by cerebellum. Q20. What is the function of fore brain? Ans. It is the main thinking part of the brain. It has regions to receive sensory impulses from various Receptors. Separate areas of fore brain are specialized for hearing, smell, sight and so on. The sensation of feeling full is also controlled by it.
